1. Field of the Invention
The invention relates to a roll forming machine and method and is particularly, but not exclusively, concerned with the production of a roll formed component for an aircraft.
2. Discussion of Prior Art
Where roll forming of components is effected on a machine, material passing through the machine is shaped by deforming and, in some cases, surfaces of the material are pressed together and webs and flanges are formed. When roll forming the material, corners are generally radiussed as it is not normally possible to form a corner with a precise sharp edge. Sometimes, where the radius is next to an adjacent radius or surface an unwanted recess is defined. Also, when manufacturing aircraft components such as wings, a lay-up of fabric such as carbon fiber is sometimes used to form the wing skin. Certain areas of the wing skin may be stiffened on the internal surfaces by means of blade stiffeners of T-shape cross section. Where a lay-up of fabric is used to produce the wings, it would be useful to manufacture blade stiffeners from similar material. The present invention is concerned with a roll forming machine and method which addresses the above points.
According to a first aspect of the invention, there is provided a roll forming machine comprising roller means for shaping a fabric such as a fabric impregnated with a curable matrix, and feed means for feeding a length of material onto the fabric during or subsequent to the shaping process.
Not only will such a machine enable a component such as a blade stiffener to be made from a fabric but it also enables material to be fed into an unwanted gap or recess in the roll formed fabric.
According to a second aspect of the invention, there is provided a roll forming machine comprising roller means for shaping a fabric such as a fabric impregnated with a curable matrix, and feed means for feeding a length of material, into or across a space created between portions of the fabric during or subequent to the shaping process.
The feed means may cause the length of material to be laid into or across a recess formed at a juncture between adjacent portions of the shaped fabric.
In the preferred embodiment, the roller means deforms the fabric so as to position the juncture between flange and web portions of the fabric. In such a case, the roll formed of fabric may be of T-shape section, the vertical limb of the T-shape forming the said web and the horizontal limb thereof forming the flange.
Means such as a roller may be provided for controlling depth of the formed fabric, for example the depth of the web portion. If desired the means for controlling the depth of formed fabric may be controllable to vary the depth progressively to form a taper. The fabric may move through the machine at a constant rate. The means for controlling depth may be arranged to form sections of various depths in the length of the material
The fabric may be in the form of a flat laminate or may be in the form of a tube such as a braid. In the latter case, the feed means is arranged to feed the length of material axially through the tube.
The length of material may comprise a tow of fibers or, instead of or in addition to the tow of fibers, a further laminate.
If desired, the fabric may be heated prior to being shaped by the roll forming machine to soften the fabric. If desired, the heating means may continue to heat the fabric as it encounters the roller means.
If desired, a lay-up station may be provided for laying up fabrics to form a laminate and means may be provided for conveying the laminate from the lay-up station to the roller means.
According to a third aspect of the invention there is provided a roll forming machine comprising a lay-up station for laying up fabrics to form a laminate, roller means for shaping the laminate and means for conveying the laminate from the lay-up station to the roller means.
According to a fourth aspect of the invention, there is provided a method of roll forming a fabric such as a fabric impregnated with a curable matrix comprising passing the fabric between roller means and feeding a length of material onto the fabric during or subsequent to the shaping process.
According to a fifth aspect, of the invention, there is provided a method of roll forming a fabric including forming the fabric immediately upstream of roller means, conveying the formed fabric to the roller means and causing the roller means to shape the fabric.